Alright here's the deal.

The car starts awesome when it's warm, and usually when it's dead cold. it's the in-between areas that it does this "stumble".

If it sits for an hour or two, sometimes more it stumbles when it starts.

I've done all the tricks that are always posted but it's like i'm missing something. It is extremely frustrating. It fires right when stat sync comes ON, it starts but stumbles a bit as the rpms raise then it clears out and runs normal. If I shut it off right then and re-start it, it doesn't do it. Only if it's been sitting for awhile.

Basic relevant mods are 950's, pump gas, single walbro, stock fuel lines/rail/regulator, stock motor/head, hks 272's.

Lemme know if any of you have anything to try.

-Trevor

 

I took a quick look at your map... everything looks pretty good. Nothing obvious out of the gate for the condition you are talking about. Turn off 02 feedback and see if it still does it.... Let me know if that makes it better or worse.

Jason

 

I originally had o2 feedback off at idle, and doesn't turn on till around 95-105*. The problem still persisted with o2 feedback off in that area.

 

Do you have any data-logs of the event?

 

I do no unfortunatly, it happened at random so I didn't want to have the laptop ready everytime i started the car. It also tore apart right now so I can't start it.

 

try interpolating your initial crank pulse table between 20 - 50c.

maybe bump up your w-up enrichment tbl @ 50 & 60c

is there any merit to having your crank adv @ 27°?

good luck

 

It seams to sync faster at 27* crank advance. I usually have it at 14.7, but it just seams to sync faster at 27*.

 

Have you tried to set-up the internal logger to capture the event... ?

 

I have not. I could do that however I'd constantly have to pull logs so I might as well just log it everytime i start it.

What exactly would we be looking for with a log. The fuel looks fine. Not too rich and not to lean. Seams when I add fuel it doesn't help then gets worse, and if i take fuel out it won't start.

 

The data sampling rate of the internal log is faster then PC logging and will capture data thats unseen in your PC log.... Crank and Cam sensors data and the other usually suspects..

 

Oh just to elaborate. I had the car starting absolutly perfect with the 680cc injectors before. Fired right up every time with no stumble or anything. Then i swapped the 950's in and I had to adjust a lot. Then after a few days the problem started and I just can't seam to find what the deal is.